Calculating machine



y 22, 1934- .R. c. COXHEAD 79 CALCULATING MACHINE Filed Sept. 13, 1924 3Sheets-Sheet l QC INVENTOR fialp/z l. Caz/z eazZ ATTORNEY y 1934- R. c.COXHEAD CALCULATING MACHINE Filed Sept. 13, 1924 3 Sheets-Sheet 2INVENTOR 4 BY a MA'I'I'ORNEY I May 22, 1934'. R. c. coXHEAD CALCULATINGMACHINE Filed Sept. 13, 1924 3 Sheets-Sheet 3 INVENTOR Ralph 6'. 'orkeadM ATTORNEY Patented May 22, 1934 UNITED STATES CALCULATING MACHINE RalphC. Coxhead, New York, N. Y., assignor to Mercedes Buromaschinen Werke,A. G., Zella Mehlis, Germany, a corporation of Germany ApplicationSeptember 13, 1924, Serial No. 737,496

.47 Claims. (01. 23562) This invention relates to improvements incalculating machines and involves means for rendering hand-operatedmachines of the universal calculating type, semi-automatic in operationwithout necessitating any material change in their design. The inventionis applicable to a number of different well known makes of machines, butfor purposes of illustration, I have shown it attached to a machine ofthe character disclosed in the United States patent to Hamann,#1,011,6l'7, of December 12, 1911.

The Hamann patent discloses a hand-operated machine for performingaddition, subtraction, multiplication and division. It includes aselector mechanism for setting up a sum to be added or subtracted, or tobe used as a factor, multiplicand, or divisor. Means are provided fortransferring such sums to a set of registering or accumulating wheelsmounted on a travelling carriage, the registering wheels having suitablecarry-one mechanism associated therewith. The .sum transferred from theselector mechanism to the registering wheels can be transferred ineither positive or negative terms, that is to say, it can be eithersubtracted from or added to the register or any amount already on theregister.

The means for predetermining whether the sum is added or subtractedinvolves a shift lever operable to predetermine whether the sum set upon the selector shall be transferred to the register in terms of theselected digits or in terms of the complements of such digits. TheHamann machine rotates the registering wheels always in one direction,and hence, in performing, subtraction, adds the complement of the actualsubtrahend to the amount, if any, on the registering wheels, but myinvention may be applied with equal facility to a machine in which theregistering wheels are reversely rotated to perform subtraction.

In performing straight addition on the Hamann machine, a sum is set upon the selector mechanism and an operating crank rotated one revolutionor stroke to transfer said sum to the register. 1n performingsubtraction, the control lever is shifted to effect the entry on theregister of the complement of the subtrahend amount set up on theselector mechanism, and the operation carried out in a similar manner.In multiplying, a factor is set up on the selector mechanism and thecrank handle is turned a number of revolutions corresponding to thefirst figure of the multiplier after which the carriage is shifted onestep denominationally and the crank handle turned a a number ofrevolutions corresponding to the second figure of the multiplier, thisoperation being repeated for each figure of the multiplier. The resultappears on the register. Any means for registering the turns in therespective denominational'places to indicate the multiplier, may beemployed.

In performing division, the dividend is set up on the register and thedivisor entered in the selector mechanism. A feature of particularimportance in performing division is the means controlled by thecarry-one mechanism of the register for automatically locking the driveshaft when, in adding or multiplying operations, the capacity of theregister is exceeded, and in subtracting operations, the amountsubtracted by complementary addition exceeds the amount registered onthe totalizer wheels.

Division, according to one method, as practiced on this machine,consists of a succession of complementary and direct adding operations,during which the machine will be locked whenever, in complementarysubtraction, the amount thus subtracted does not exceed the capacity ofthe register, and also when directly adding the amount so added doesexceed the capacity of the register. In other words, when performing anoperation in division, the traveling carriage is so adjusted relativelyto the keyboard as to position the first figures of the dividend enteredon the right-hand wheels of the register mounted in the travelingcarriage, in approximate alignment with the first figures of the divisorset up on the selector mechanism. Having set the shift lever to itsSubtract-Divide position, the main crank is turned to repeatedlysubtract (by complementary addition) the divisor set up on the selectormechanism from the dividend on the register, until nines" appear on allthe register wheels to the left of that on which the digit of highestdenomination in the dividend was registered. The occurrence of suchcondition (the appearance of nines") indicates that the divisor has beensubtracted once too often from the dividend. At the completion of suchexcess subtracting operation, means controlled by the register operatesautomatically to lock the main drive shaft and its crank againstrotation. When the operator is notified, by his inability to furtherrotate the main crank. that the machine is locked, from which conditionhe knows that the divisor has been subtracted once too often, he adjuststhe shift or state-controlling lever to its Add- Multiply position.

The shift or state-controlling lever, when adjusted from either of itspositions to the other,

operates to unlock the drive shaft and enables the register carriage toshift one step to the left automatically. The register carriage, by suchone-step shift, increases the partial dividend under treatment in muchthe same manner as occurs in the mental performance of division. Withthe state-controlling lever in its Add--- Multiply position, theoperator turns the released main crank, to repeatedly add the divisor tothe increased partial dividend until ciphers appear on the totalizerwheel to the left of the digit of highest denomination remaining on thetotalizer.

The presence of zeros at this stage of the operation indicates that thecapacity of the totalizer has been exceeded by. the addition of thedivisor once too often to the dividend, and such condition enables thetotalizer to again effect an automatic locking of the machine againstfurther operation.

Thereupon, the operator manually shifts the state-control lever from itsAdd-Multiply to v its Subtract-Divide position, whereby to againcondition the machine for complementary subtraction, release theautomatic lock, and enable the totalizer carriage to shift another stepto the left to again increase the partial dividend under treatment. I

The foregoing conditions having been effected,

the operator again repeatedly operates the ma-.

chine, as in the first stage, until the excess subtraction of thedivisor from the dividend again results in an overdraft registration andthe appearance of nines on those totalizer wheels to the left of theWheel bearing the digit of highest denomination of the remainder of thedividend. Such operations are alternately carried out until the sum isdivided out as far as possible with a remainder, if any, on theregister. A suitable quotient-indicating mechanism controlled from thecrank shaft and mounted on the carriage, indicates the quotient in termsof crank shaft revoiutions. This indicator is equipped with a reversiblecarry-one mechanism for eliminating the indication of the extrarevolution of the shaft upon the first revolution in a reverse directionafter having subtracted or added the divisor once in excess of thenumber of times it is receivable into the partial dividend undertreatment.

In accordancewith the illustrated embodiment of my invention, whichinvolves rendering amachine of the above described general charactersemi-automatic in operation, I utilize a motor instead of a crank forturning the main operating shaft, but I may retain the manual shiftlever for predetermining the addition orsubtraction of the sum selectedto or from the sum on the register. The carriage maybe denominationallyfed either manually or automatically. The methods of performing additionand subtraction remain the same except that instead of turning the crankshaft, a suitable clutch-controlling member may be manually operated toconnect the motor with the drive shaft for a single revolution.Preferably, this clutch-controlling member is in the na-.

ture of a depressible, springeopposed push button or bar operable upon amain clutch-controlling lever normally holdingthe clutch out and adaptedto free the clutch for engaging with the main operating shaft when thebutton or bar is depressed. In performing multiplication, the

clutch-controlling push button is held down manually until the motor hasturned the drive shaft the desired number of revolutions, fcreach digitof the multiplier, after which the clutch-controliing push button, isreleased by ape-rater to reserve enable the main clutch controllinglever to restore to effective position.

In performing division, however, it is obviously diflicult to estimatethe exact number of revolutions required of the operating shaft and theuse of the motor consequently involves the use of a supplementalclutch-controlling member for automatically throwing out the clutch atthe proper times, even though the button is still held depressed.Preferably, the operation of this supplemental clutch controlling meansis governed by the standard carry-one mechanism for the registeringwheels and is operable to automatically disconnectthe clutch on therevolution during which the register has in effect sub tracted backthrough zero or added forward through 999, etc.

A preferred embodiment of the invention includes means associated withthe main or push button control for holding the supplementalclutch-control member inoperative whenever the push button control isnot manually held efiective. When'the push button is depressed, however,the means for causing; the supplemental control to disconnect the clutchupon that revo- -matically restores to effective position in the path ofthe clutch arm 32 to hold the clutch members disengaged, and in sodping, will automatically restore the supplemental clutch control memberto inoperative position where it will be held until, upon a reversal ofthe shift lever and another depression of the push button incontinuing'the operation of division, the capacity of the regismr isagain exceeded in repeated additions of the actual divisor thereto, ornot exceeded in repeated additions of the complement of such divisor.The push button control thus serves as a re-set mechanism for thesupplemental control member.

My invention may also include the use of an automatic locking device ofparticular importance in performing division, such locking device beingoperable to hold the main clutch control lever effective until the shiftlever has been adjusted. Thus, when the machine has been set for eitheran adding or a subtracting operation, and

" in the performance of its work, the machine becomes idle due to theaction of the automatic clutch control, under the above-explainedconditions, it is not possible to start the machine Liz-f bemanufactured and sold as an attachment for,

the older type of machine.

It is to be borne in mind that, while I have shown my invention asapplied to one well known type of machine, the principles involved maybe readily adapted for application to. practically any make of wiversalcalculating machine, without necessitating material changes either inthe basic design of the machine or the construction of m novelmechanism.

The details of the motor attachment and its associated mechanism may bebetter understood from the accompanying drawings in which variousdetails of the old standard type of machine have been omitted for thesake of clearness, only such conventional mechanism being shown as isnecessary to a clear understanding of the construction and operation ofthe clutch control selected to illustrate one embodiment of theinvention.

In the accompanying drawings Figure 1 is a broken plan view of acalculating machine embodying the invention,

Figure 2 is a right end view on the line 2--2 of Fig. 1,

Figure 3 is a transverse section on the line 3-3 of Figure 1 lookingtoward the right,

Figure 4 is a transverse section on the line 4-4 of Figure 1,

Figure 5 is a transverse section on the line 55 of Figure 1 lookingtoward the left.

Inasmuch as the selector mechanism. or keyboard, the carriage feed, themeans for transferring sums from the selector mechanism to the register,the quotient-indicating mechanism, register clearing mechanismandnumerous other details of the machine shown in U. S. patent toHamann, 1,011,617, issued December 12, 1911, form no part of the presentinvention, they have been entirely omitted from the drawings. I haveshownv only such standard parts of the Hamann machine as are necessaryto an understanding of my improved mechanism and the standard parts havebeen indicated in light lines.

The frame work of the machine may conveniently include a rectangularhousing accommodating any suitable type of selector mechanism (notshown). Shfftablelongitudinally in front of the housing 10 is atravelling carriage 11 (Figs. 1 and 3) in which there are mountedtransverse shafts 12 carrying registering wheels 13. In Figure 1, I haveshown only the shaft of the highest or left hand digit wheel since it ispreferably from this shaft that the automatic clutch-controlling devicesare'operated, although any predetermined wheel of the register-may beutilized for the purpose. The conventional main driving shaft 14 isjournaled vertically in the walls of the housing 10 near the right handend of the machine, this shaft serving to drive the transfer wheels,(not shown) which couple the selector mechanism with the register at theproper times, and serving also to operate various other devices, such asthe cam shaft 15 (Fig. 3). This shaft is journaled in the forward end ofthe machine frame below the carriage and carries cams 16 which engagewith the rollers 17 at the lower ends of vertically sliding carryingmembers 18 which form part of the carry-one mechanism for theregistering wheels 13 on the carr'age. The means by which the verticalslides 18 effect transfer from one wheel to another is not material tothe present invention and the way in which the slide of the last digitwheel effects control of the driving motor will be more fully explainedhereinafter.

In applying a motor drive to a machine of this character, the motor 19Figs. 1 and 2) may be mounted in any convenient position. I find that Iam able to obviate the necessity for making any material changes in thestandard construction of the machine by mounting the motor on a frameplate 20 secured under the machine or to the end of the housing 10 whichis adjacent the drive shaft 14. Numerous expedients might be reresortedto for properly gearing the motor to the shaft 14, and for purposes ofillustration, I have merely shown one convenient power transmittingmechanism, which includes a worm shaft 21 axially aligned with the shaft22 of the motor and directly coupled thereto by a clutch 23. Shafts 21and 22 are mounted in suitable bearings 24 prol'ecting laterally fromthe frame plate 20. A worm 25 on the worm shaft 21 meshes with a wormwheel 26 on a vertical counter-shaft 27, the bearings 28 of which arecarried by the frame plate 20. The upper end of the countershaft carriesa gear 29 fast thereto meshing with a similar-gear 30 fast on the mainshaft 14 of the machine.

Worm wheel 26 is loose on the shaft 27 and is adapted to be readilycoupled thereto and uncoupled therefrom through the intermediacy of aclutch 31 (Fig. 2). This clutch may be of any suitable design and may bemechanically or magnetically operated. Preferably, however, a frictionclutch is used, the radially projecting arm 32 of which controlsengagement of the friction members in a conventional manner. This arm ispreferably normally spring-pressed into clutchengaging position and maybe kicked out or swung against the action of its spring to disconnectthe two rotatable members 31a, 31b of the clutch, to permit idlerotation of member 31a and d'sconnection of the driving shaft 27 and themotor. I have not illustrated the details of construction of the clutchinasmuch as they are entirely conventional.

The main clutch-controlling member preferably comprises a depressiblepush button 35 (Fig. 4) carried on a vertically movable rod 36 mountedin and passing upwardly through the top of the casing 10, the rod beingnormally held in its upper or outer position by a coiled spring 45.Depression of the rod 36 against the action of its spring rocks a cranklever 38 having a hub 39 journaled on a stud shaft 40, said crank leverincluding a knobbed extension 41 engageable in an opening 42 in one endof a clutch-controlling lever 43. Lever 43 is pivoted intermediate itsends on a stud 44 (Fig. 1) and is normally retained by the spring 45 inthe position shown in Figure 1 of the drawings, where its free end 46 isdisposed in the path of the clutch arm 32, to hold out or maintaindisconnected the two members of the clutch 31. When the push button 35is depressed, it operates through the medium of the crank lever 38 toswing the clutch-controlling lever 43 on its pivot and move the free end46 of the lever out of the path of the clutch arm 32, thereby permittingthe spring-urged clutch members 31a, 31b to couple the motor with theshaft 14 and drive the machine.

In performing addition or subtraction, a sum set up on the selectormechanism may be transferred to the registering wheels by simplydepressing the push button 35 to cause the clutchcontrolling lever 43 torelease the clutch arm 32, whereupon the clutch members 31a, 31b auto--matically connect the motor with the main drive shaft 14 to turn thelatter.

The action of the clutch members is so rapid that the push button may bealmost immediately released. when adding a series of items, where- ISi'efieots disconnection of the clutch members in a v For convenience ofdescription, '1 have rewell-kncwn manner. In performing multiplication,a multiplicand is set up on the selector mechanism. The push button isthen held down until the machine has made a number of revolutionscorresponding to the highest figure of the multiplier, after which thecarriage is shifted denominationally and the operation repeated for theremaining numerals of the multiplier. The presence of indicatingmechanism, which is not illustrated but which forms a conventional partof machines of this character and indicates crank shaft revolutions,makes it a comparatively simple matter to multiply correctly by simplyholding down the button and watching the indicator until the correctnumber has been reached. Similar results may be had by starting tomultiply by the lowest figme of the multiplier and shifting the carriagedenominationally in the opposite dilem is presented since division isperformed on the machine by a series of adding and subtractingoperations. The divisor set up on the selector mechanism is firstsubtracted by complementary addition from the dividend set up on theregister once too many times, or in other words, subtracted until theregister is over-run through 999 etc, after which they machine must beset for addition, the carriage shifted, and a number of addingoperations performed until the divisor has been added to the partialdividend the proper number of times to exceed the capacity of theregister. After the register has been over-run either by adding theretothe exact amount set up in the selector mechanism, or by adding thecomplements of such amount, the shiftlever so which predetermineswhether sums on the selector are transferred to th register in terms ofequivalents or complementsgmust be operated. It is impracticable towatch the register to predetermine which revolution of the shaft 14 willresult in over-running the register or carrying beyond its limits, andconsequently I find it necessary to employ a supplemental automaticclutch-controlling means which will positively disconnect the motor fromthe shaft 14 at such times.

The supplemental clutch control member is preferably locked againstactuation by means under control of the carry-one mechanism of thehighest or last left hand registering wheel 13, to retain thesupplemental clutch control member idle unless and until the capacity ofthe register is exceeded. This supplemental clutch control memberincludes a lever 51 (Fig. l) pivoted ad jacent one end on a stud 52,fixed to the machine frame and including a free end movable into thepath of the clutch-arm 32, when the supplemental clutch-control lever isreleased for operation by the carry-one mechanism and swung clockwise onits pivot. A spring 53 normallyv tends to urge the lever into positionto effect the disengagement of the clutch members, but when theclutchcontrolling lever 43 is in its efiective position shown in Figure1, the lever 51 is held inoperative by the engagement of the projection54 on the clutch-controlling lever 43 with a similar extension 55-on thelever 51 to rock the lever 51 countor-clockwise about its pivot and holdit in the position shown in Figure 1. To accomplish this result, it is,of course,'necessary ,that the spring 45 be considerably stronger thanthe spring 53 to zero.

. as the carry-one mechanism of any other selected registering wheelmight serve the same purpose.

The slide 18, at its upper end, carries a pair of horizontally disposedrelatively ofiset arms 60, 60a (Figs. 1 and '3) adapted, respectively,for engagement with relatively offset fingers 61, 61a projecting fromopposite ends of a trip plate 62 pivotally and slidably mounted onashaft 63, journaled in the carriage adjacent and parallel with the lastcounter wheel shaft 12. The trip plate is shifted back and forth on theshaft 63 whenever the position of the shift lever 50 is changed, bymeans such as is disclosed, for-instance, in the Hamann Patent1,011,617, above referred to. A sleeve 64 sliding on the shaft 12carries at one end an annular flange 65 cooperable with theslide 18 onthe left to tilt the same laterally toward the trip plate 62 as theslide is lifted by the cam 16. Means (not shown, but fully disclosed inthe patent to Hamann, above mentioned) are provided for sliding thesleeve 64 forwardly on the register wheel shaft 12 whenever theregistering wheel 13 passes from nine Consequently at such time, theflange 65 will be in position to tilt the slide 18 as the latter israised by its cam 16, and swing the arm 61 when the machine is set forsubtraction. The

position of the trip plate 62 illustrated in Fig. 1,

is the position it assumes when subtractionis being performed on themachine. Consequently, as long as the last registering wheel makes acomplete rotation at each revolution of the driving shaft 14, the sleeve64 will slide forward at each operation to position its flange 65 in thepath of the carrying member 18 of highest order to crowd the latter withits arm 60 to the left, so that during its upward travel, the arm willnot contact the finger 61; As soon, however, as the complement of anegative amount appears on the register, or in other words, when thewheel 13 of highest denomination fails. to make a complete revolution,the sleeve 64 will not move forwardly, and the arm 60 will engage thefinger 61 and trip the plate 62. When the trip plate is in its oppositeextreme position, as in adding the exact amounts set up on the selectormechanism, the finger 61a will coact with the arm 60a, and a reversecondition is set up in which the arm 60a is arranged to clear thefinger-61a in normal adding operations, but will swing over and lift thefinger and its trip plate 62 whenever the flange 65 is in its forwardposition. In other words, as long as the last registering wheel remainsbelow nine, the plate 62 will not be tripped, but as soon as thecapacity of the wheel of highest denomination is exceeded from nine" tozero, the'fin'ger 60a will become operative and trip the plate. Thisoperation of the carry-one mechanism to trip the plate 82 is entirelyconventional, and is clearly explained in the Hermann patent referredto.

its

Novel mechanism is utilized to establish an operative connection betweenthe trip plate 62 and the supplemental clutch controlling lever 51. Ashaft 6'7 is journaled in the ends of the carriage 11 and carries afinger 68, the free end of which is disposed under the trip plate (Figs.1 and 3) and adapted to be depressed whenever the trip plate is rockedby one of the arms 60, 60a. Rocking movement of the finger 68 will tendto partially rotate shaft 6'7 to swing a blade 68 (Figs. 1, 2 and 5)sweated to and extendin radially from the shaft 67, into engagement withthe free end of a thrust bar 69 which is guided in a bracket '70 securedto the main frame of the machine. The opposite end of the thrust bar 69is articulated with one arm of a suitably pivoted bell crank lever '71to rock the latter counter-clockwise (Fig. 5). A pin '72 pivoted at oneend to another arm of the bell crank lever '71 has its free end normallydisposed within an opening '73 in the supplemental clutch control lever51 to normally retain this lever in the idle position shown in Figure 1.Rocking the bell crank under the influence of the thrust rod 69 aga'nstthe influence of a tension spring '70 retracts the pin from the openingin the supplemental clutch-controlling lever 51.

It is to be remembered the trip plate 62 can only become operative whilethe machine is run ning. Depression of the control button 35 operates toswing the clutch-control lever 43 out of the position shown in Fig. 1,to a position where the projection 54 of the lever 43 cannot act on theextension 55 of the supplemental lever 51.

As a result, the supplemental clutch control lever 51 is free to swinginto the path of the clutch-arm 52 under the influence of its spring 53,whenever the pin '72 is withdrawn by the carry-one mechanism as thecapacity of the register is exceeded.

Thus, in the operation of division, when the machine is set for eitheraddition or subtraction and the push button control 35 is held down, thetrip plate 62 will become active when the capacity of the wheel 13 ofhighest denomination in adding operations is exceeded, or upon failureto exceed such capacity when subtracting by complementary addition torelease the supplemental control lever 51 for operation, to disconnectthe motor from the drive shaft. The shaft or rod 67 serves as a veryconvenient means for transferring motion from the trip plate 62 at oneend of the machine to the clutch control lever 51 at the other end ofthe machine. The rod is preferably given a rotary movement, asdescribed, but may either be pivoted, slid or otherwise moved inaccordance with the problems presented in various types of machines andthe arrangement of other operating parts on the carriage. As a matter offact, the rod 67 is not necessarily mounted on the carriage but could bemounted on the frame of the main casing 10, in which case, the finger 68would be arranged to slide along the rod as the carriage was shifted.

Disconnection of the clutch 31 warns the operator that the registeringcapacity has been exceeded, in adding operations, or that it has notbeen exceeded in subtracting operations, and if he is performingdivision, it indicates that the lever 50 should be shifted beforeproceeding. The carriage shifting mechanism (not shown herein but fullydisclosed in the Hamann patent heretofore referred to) is preferablycontrolled directly from the lever 50 so that the only operationnecessary, if the machine is stopped while performing division, is toshift the lever 50.

I find it desirable and of particular advantage when the machine isbeing operated by an unskilled operator, to provide means which willmake it impossible to start the machine after the motor has beendisconnected from the machine by the supplemental clutch control, unlessthe lever 50 is first shifted. I accomplish this by the use of anotherlocking pin '75 (Figs. 2 and 5) which may be set into a hole '76 inthe'lever 43 to retain this lever in clutch disengaging position untilthe lever 50 has been shifted. The locking pin '75 may be guided at itsupper end in an opening '77 in the bell crank '71 and is normally heldin the elevated position shown in Figure 5 by a finger '79 carried by atransversely extending rock shaft journaled in the main frame of themachine. Finger '79 engages a collar 81 on the pin to lift the same, aspring 82 acting on the finger and rock shaft 80 to retain them normallyin the positions shown in Figure 5. The bell crank '71 is provided witha keeper in the nature of a prong 83 which normally supports the Whenthe free end of a flat spring 84 (Fig. 2). bell crank is rotated by thethrust rod '79, the keeper moves out from under the end of this springand permits it to snap downwardly, de-' pressing the pin '75, againstthe tension of the inferior spring 82. -At the time that the thrust rodis actuated, the clutch-control lever 43 will be held ineffective by thepush button 35 and consequently, as the spring 84 moves downwardly, itwill press the pin against the upper surface of this lever closelyadjacent the hole 76 therein, as indicated in Figure 5. As soon,however, as the push button is released to permit the clutchcontrollever 43 to move into effective or clutch disengaging position and todisable the supplemental clutch-control lever 51, the pin '15 will dropinto the opening 76 of the lever 43 after the latter has shifted toeffective position relatively to the clutch, the end of spring 84 beinglowered sufficiently to enable it to block the return of the bell crank'71 and of the locking pin 72 to their normal positions.

It will be understood that the main clutch control lever 43 must havebeen held in its idle position by pressure on the push button 35 so asto remove the projection 54 of the main control lever 43 from the pathof the opposed projection 55 on the supplemental control lever 51, inorder to enable the automatic operation of the supplemental clutchcontrol lever 51 to its effective position upon the release of thelocking pin '72.

Therefore, the main control lever 43, upon its return to effectiveposition, due to release of the push button 35, and as an incidentthereto, operates under the influence of its spring 45 and through itsprojection 54 and the projection 55 on the supplemental control lever51, to automatically shift the supplemental control lever back to itsidle position.

The supplemental control lever 51 is arranged to disable the clutch at apoint in the. cycle of travel of the clutch sufliciently in advance ofthe point at which the main control lever 43 disables the clutch, sothat the latter lever can assume effective position in time to againarrest the clutch arm after its release by the supplemental clutchcontrol lever upon the automatic restoration of the supplemental leverto idle position, at the completion of such cycle of travel.

The supplemental lever 51 on its return to its idle position, re-locatesthe hole or aperture 73 in line with the locking pin '72.

spring 84 to prevent the latter from acting uponv It is now impossibleto startthe machine by dep the push button 35, since the pin '15 holdsthe lever 43 against movement, and in order that operation of themachine may be resumed, it is nec to shift the lever 50, which, throughthe medium of a link 86 (Fig. 3) pivotally connected thereto, actuates arelease mecu m for the pin 75. This release mechanism preferablycomprises a bar 87 pivo to the 86 and having a reduced end 88 sliding ina guide way 89 as the lever 50 is shifted. The upper surface 01' the bar87 includes a fiat portion 90 against which a finger .91 on the rockshaft 80 bears as the spring as becomes active to depress pin and rotatethe rock shaft through the collar 81 and the arm 79. As the lever 50 isshifted, a cam 92 which interrupts the intermediate portion of the flatsurface 90, is forced against the finger 91 to elevate the finger andturn the shaft to positively lift the pin 75 out of engagement with theclutch-control lever 43 against the action of the spring 8d. As this pinis lifted through the medium of the finger 79, and the collar 81, itforces the leaf spring 84 upwardly so that its free endclears the upperend of the prong 83,

whereupon the bell crank '21 snaps back to normal tion by the action ofits spring '10 and introduces its prong beneath the free end of the thepin 15. The spring 82 is thus permitted to retain the pin 75 in elevatedposition. As the bell crank 71 snaps back to normal position, it causesthe locmng pin 72 to re-enter the hole or aperture 73 in thesupplemental clutch-controlling levera'il to maintain the latter idleunder control of the carry-one mec of highest order, and the push button35 and main clutch control lever 43, until the capacity of the machineis e lexed while the oz:- control lever is in idle s: It will be notedthat or stop of the machine by release of the push button 35 isinefiective to lock lever 43 by the pin 75 sincethe keeper 83 alwaysholds the spring 84 inactive until such time as the sup plemental clutchlever 51 is freed from its own :11 pin 72, and operates to disengage theclutch. In other words, the race of the pin 75 and its assoc any chanceinterfere with the or 1..-

bed II 51.1, m can never by 1 p s and starting of the machine, whichoccurs when perio addition, subtraction, and tip cation, unless, inperio such operatiom, the register is beyond its limit. If it were nottor the of the locmng pin 75, it would be possible to reset theautomatic clutch-control lever 51 by rel as 1.: the push button 35, andcontinue the operation of the n w: imp erlv. By e or my improvedattachment, the machine is rendered fool proof by the automatic lockingof the clutch control levers 43 and 51 until the position of the shiftlever 50 has been rev r -1 I have illustrated and described merely onepreferred -ox" nt of the invention. It will be obvious that 1r. tionsmight be e in the general form and arrangement of the described withoutde- 1. from the invention, hence I do not wish to limit If to thedetails set forth, but shall consider myself at y to changes andalterations w fairly fail the spirit and scope of the'certainoitheiusethe w r i of said ee i has been notedthat'attimesaniisedtotheq reserve J tity standing on the register and atother times the complement of said item is added instead; inorder todefine such an insertion into the register I use the term above quoted.

'I claim: 1

1. In a motor driven" calculating machine includingdifierential'mechanism for mechanically representing an item with meansfor tr ting a form or said mechanically represented item to a set ofregistering wheels; the combination with a clutch controlling the tionof power from the motor to the register, said clutch including a controlarm a lever normally spring held in the path of the clutch arm, to holdthe clutch disengaged, and manually operable means for swinging thelever out of the path of the arm to permit engagement of the clutch; ofa. supplemental lever automatically controlled by the register, upon theoccurrence of a predetermined condition therein, and movable into thepath of the arm to disengage the clutch whenever the form of said itemmust be changed.

2. In a motor driven calculating machine, in-

eluding a register; difierential mechanism for represented item to theregister; the combinetion with a clutch controlling the transmission ofpower from the motor to the register, said clutch including a controlarm; of a lever normally in the path of the clutch arm, to hold theclutch disengaged, and manually operable means for swinging the leverout of the path of the arm to permit engagement of the clutch, aspring-urged supplemental lever automatically controlled by the registerand movable into the path of the arm to disengage the clutch wheneverthe form of said itemmust be changed.

3'. In a motor driven calculating machine, in cluding selectormechanism; a register con= trolled thereby; and a clutch for controllingthe transmission of power to the machine; of means associated with theregister for disabling said clutch when the registering wheels reach apredetermined state said means including a tripplate under control ofsaidregister, a rock shaft actuated by said trip plate, a clutchcontrolling lever normally locked in inactive position means actuated bythe rock shaft to release said lever to enable it to move into clutchdisabling position. a second controlled clutch lever nolly urged toclutch-disengaging position, and means for manually moving saidlast-named lever out of clutch disenw a. In a motor driven calculatingmachine inclu a selector mechanism for me- 1:..- :9 represen an item;means for ttting a form of said mechanically represented item to theregister; the combination with a t to operate the t tting mech and, aclutch for connectg and disconnecting said shaft and motor; of meansassociated with the register for disabling said clutch when the wheels ha predeteed state said means inclu a trip plate under control of saidi", a rock t actuated by said tion, resets the first-mentioned clutchlever to itsinactive position.

5. In a calculating machine, including a register on which values may beadded or subtracted; the combination with a drive shaft for operatingthe machine; co-acting clutch members interposed between the drive shaftand the machine; manually-operable means to control connection anddisconnection of the clutch members, under normal operating conditions;and a state-controlling inechanism to predetermine whether the valuesshall be added or subtracted on the register; of register-controlledmeans to automatically render the clutch inoperative when the registerattains a predetermined condition at a time when the manually operablemeans is in its ineffective position; and means also under control ofthe register to lock the manually operable clutch control means in itseffective position upon its return thereto until the state-controllingmechanism has been operated.

6. In a machine of the class described, the combination with a registeron which numbers may be added or subtracted; a shaft to operate themachine; a clutch interposed between the shaft and the machine; and astate-controlling mechanism to predetermine whether a number shall beadded or subtracted; of clutch-releasing means automatically operable todisengage the clutch; a second clutch-releasing means normally operablemanually to enable engagement and disengagement of the clutch; and meansrendered operable by the automatic clutch-releasing means, to co-actwith the second clutch releasing means to prevent operation of themachine until the state-controlling mechanism is re-adjusted.

7. In a machine of the class described, the combination with a registeron which numbers may be added or subtracted; a shaft to operate themachine; a clutch interposed between the shaft and the machine; and astate-controlling mechanism to predetermine whether a number shall beadded or subtracted; of clutch-releasing means automatically operable todisengage the clutch; and a second clutch-releasing means normallyoperable manually to enable the clutch to transmit power to the machine,and adapted to be automatically locked in clutch-disengaging position bythe operation of the first-named clutchwith a register on which numbersmay be added or subtracted; a drive shaft for operating the machine; aclutch to render the drive shaft effective or ineffective; and astate-controlling means to predetermine whether a number shall be addedor subtracted on the register; of manually operable clutch controlmeansto render the clutch effective and ineffective; register-controlledmeans to automatically render the clutch ineffective; and normally idlemeans releasable for operation by the automatic clutch control, andoperable upon restoration of the manual clutch control means to clutchdisengaging position, to lock the manual clutch-control.

9. In a calculating machine, the combination with a register on whichnumbers may be added or subtracted; a drive shaft for operating themachine; a clutch to render the drive shaft effective or ineffective;and a state-controlling mechanism to predetermine whether a number shallbe added or subtracted on the register; of manually operable clutchcontrol means to render the clutch effective and ineffective;register-controlled means to automatically render the clutchineffective; means under control of the automatic clutch-disengagingmeans, to lock the manual clutch control in clutch-disengaging position;and means controlled by the state-controlling mechanism to disengage thelocking means and the manual clutch control, to free the latter formanual operation.

10. In a calculating machine, including a register on which numbers maybe added and subtracted; and a drive shaft to operate the machine; thecombination with a clutch to render the drive shaft effective orineffective; and a state-controlling mechanism to. predetermine whethera number shall be added or subtracted on the register; of a manuallyoperable, clutch-control member normally adapted to hold the clutchdisengaged; an automatically operable clutch-control member to effectdisengagement of the clutch when the register attains a predeterminedcondition; means controlled by the manually operable clutch-controlmember upon its return to normal position to reset the automaticallyoperable clutch-control member; locking means released for operationwhen the register attains said predetermined condition, and effectiveupon the return of the manually operable clutch-control member to normalposition, to lock such member against further operation; and meanscontrolled by the state-controlling mechanism to unlock the manuallyoperable control member.

11. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft for the machine; aclutch to render the shaft effective 'or ineffective; and astate-controlling mechanism to determine whether a number shall be addedor subtracted on the register; of a manually operable clutchreleasemember adapted to normally hold the 115 clutch disengaged; a second,normally idle, clutch-release member automatically operable to effectdisengagement of the clutch; means to restore the automaticclutch-release member to its normal position and operable incident tothe 120 return of the manually-operable clutch release member to itsnormal position; and means operable upon the return of the manuallyoperable clutch member to its effective position, to lock the member insuch position. 125

12. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft; a clutch to renderthe drive shaft effective or ineffective, including a control arm; aclutch-releasing member; means 130 to yieldingly retain theclutch-releasing member in, and return it to, its normal position in thepath of the control arm, to hold the clutch disengaged; and manuallyoperable means to shift the clutch-release member out of the path of 135the arm to enable engagement of the clutch; of a normally idle,supplemental clutch-release member and register-controlled means toenable the supplemental clutch-release member to shift into the path ofthe control arm to disengage the 140 clutch, when the manually-operableclutch-release member is out of the path of the control arm.

13. In a calculating machine, including a register on which numbers maybe added and subtracted; the combination with a drive shaft; a clutch torender the drive shaft effective or ineffective; and a manually operableclutch control member; of a second, normally idle, clutch controlmember; means to shift the normally 150 idle clutch control member toeffective position; releasable means to retain the normally idleclutch'controlmember in its idle position; means to trip the releasablemeans and free the normally idle clutch control member to the action ofits shifting means; and inter-engaging means on the respective controlmembers so arranged that the manually-operable clutch control member, asit shifts in one direction, will move the normally idle clutch controlmember in the opposite direction.

o 14. In a calculating machine, the combination with a motor; and aclutch interposed between the motor and the machine to control thetransmission of power to the machine; of a clutch control member; meansto shift the clutch control member to interrupt the transmission ofpower to the machine; a manually-operable clutch control member adaptedto establish and disestablish the clutch irrespective of the firstnamedclutch control member; and means whereby the manually operable clutchcontrol member, during its travel to one of its positions, shifts thefirst-named clutch control member.

15. A calculating machine, including a register on which numbers may beadded and subtracted; a state-controlling mechanism for predeterminingwhether the number shall be added or subtracted; a shaft, including aclutch for driving said machine, means normally operable to hold saidclutch disabled, manual means for enabling said clutch, andregister-controlled means to automatically disable said clutch while themanually-operable clutch-enabling means is held in its'inefiectlvepontion.

16. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft to operate themachine; a clutch to render the drive shaft effective or inefiective;and a shift state-control mechanism to predetermine whether a numbershall be added or subtracted on the register; of a manually-operableclutch control member normally shiftable into and out of eflectiveposition relatively to the clutch; and a register-controlled clutchcontrol member normally idle with respect to the clutch, andautomatically shiftable under control of the register into efiectiveposition relatively to the clutch when the manually-operable clutchcontrol member is out of its efiective position.

17. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft to operate themachine; a clutch to render the drive shaft efiective or ineffective;and a state-control mechanism to predetermine whether a number shall beadded or subtracted on the register; of a manually-operableclutch-control member normally shiitable into and out of effectiveposition relatively to the clutch; a normally idle, automaticallyomrable clutch-control member; register-controlled means to rendereffective the normally idle clutch-control member; and means to enablethe manually operable clutch-control member to positively re= store theautomatically operable clutch-control member to its normal position.

18. In a calculating machine, including selec= t'or mechanism, thecombination with a register; a drive shaft to operate the machine; and aclutch to render the drive shaft effective or inefiective; of amanually-operable clutch control member shiftable intoand out ofefie'ctlve position relatively to the clutch; a supplemental clutchcontrol "mtuable relatively to the manually-operable clutch controlmember when the latter is in one of its positons; means to return thesupplemental clutch control member as the manually operable clutchcontrol member moves to its other position; and means released with thesupplementali clutch control member, to lock the manual-operable clutchcontrol member when in its last-named position.

19. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft to operate themachine; a clutch to render the drive shaft efiective or ineffective;and a manually-operable clutch operable state-control mechanism, theoperation of which is enforced by the automatic locking means; and meanscontrolled by the state-control mechanism to release the locking means.

20. In a calculating machine, the combination with a register on whichnumbers may be added and substracted; and a drive shaft to operate themachine; of a clutch to render the drive shaft efiective or inefiective;a manually-operable clutch control member shiftable into and out ofefiective position relatively to the clutch; and a supplementalregister-controlled clutch control member shiftable to effectiveposition when the manually-operable clutch control member is in itsineifective position.

21. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; and a drive shaft to operate themachine; of a clutch to render the drive shaft efiective or ineffective;a manually-operable clutch control member shiftable into and out ofefiective position relatively to the clutch; and normally-idle,register-controlled means, releasable for operation by themanually-operable clutch control member, to automatically shift intoefiective position relatively to the clutch, "when the manually-operableclutch control member is inefiective.

22. In a calculating machine, the combination with a register; and adrive shaftto operate the machine; of a clutch to render the drive shafteffective or inefiective; a manually-operable clutch control membershiftable into and out of efiective position relatively to the clutch;automatically operable means shiftable into effective positionrelatively to the clutch to control the latter, when themanually-operable clutch control member is inefiective; normallyeilective lookingmeans for the automatic clutch-control means; andregister-controlled means to release the locking means to free theautomatic clutch control means for operation.

23. In a calculating machine, the combination with a register; and'adrive shaft to operate the machine; of a clutch to render the driveshaft 'eflective or inefiective; a manually-operable clutch controlmember shiftable into and out of efiectlve position relatively to theclutch; automatically operable means shiftable to effective positionrelatively to the clutch to control the latter, when themanually-operable clutch control member is inefiective; normallyefi'ective locking means for the automatic clutch-control means;register-controlled means to release the locking means; and meanscontrolled by the manuallyoperabie clutch control member to restore theautomatic clutch-control means to its normal position. 7

24. In a calculating machine, the combination with a register; of adrive shaft to operate the control member normally shiftable'relativelyto the clutch; av supplemental clutch control member; locking means tonormally maintain the supplemental clutch control member in idleposition; normally idle, locking means for the manuallyoperable clutchlever; and automatically operable means to disable the locking means forthe supplemental clutch control member, and enable the locking means forthe manually operable clutch control member.

25. In a calculating machine, the combination with a register; a driveshaft to operate the machine; a clutch to render the drive shafteffective or ineffective; a state-control mechanism to predeterminewhether an amount set up on the selector mechanism shall be added orsubtracted; and a manually-operable clutch control member shiftablerelatively to the clutch; of means to enforce a predetermined manualsequence of operations, including a supplemental clutch control member;locking means to normally hold the supplemental clutch control member inidle position; normally idle locking means for the manually-operableclutch control member; means to disable the locking means for thesupplemental clutch control member, and enable the locking means for themanually-operable clutch control member; means to thereupon render thesupplemental clutch control member effective relatively to the clutch;means controlled by the manually-operable clutch control member on itsreturn to effective position to restore the supplemental clutch controlmember to idle position, and to enable the lock for the manuallyoperableclutch control member to become eiIective; and means controlled by thestate-control member to restore the lock for the manuallyoperable clutchcontrol member, to idle position and free for operation the lock for thesupple 'mental clutch control member.

26. In a calculating machine, including selector mechanism and aregister; of a drive shaft to operate the machine; a clutch to renderthe drive shaft effective or ineffective; a manually-operable clutchcontrol member shiftable relatively to the clutch to control the latter;normally idle supplemental clutch-control means relatively to which themanually operable clutch control member is shiftable; means controlledby the manually operable clutch control member to retain thesupplemental clutch control means in idle position; andregister-controlled means to render the supplemental clutch controlmeans effective upon the clutch when the manually operable clutchcontrol member is ineifective.

2'1. In a motor driven calculating machine, the combination with aclutch to control the transmission of power from the motor to themachine,

lever out of the path of the clutch-control arm asthe manually-operablelever is spring-returned to, its normal position.

28. In a motor driven calculating machine, the combination with a clutchto control the transmission of power from the motor to the machine; aclutch control member normally efiective relatively to the clutch tohold the clutch disengaged; and manually-operable means to'shiit thelever to its ineffective position to enable engagement o! the clutchmembers; of a normally idle supplemental clutch-control member shittableinto and out of eflectiveposition relativeLv to the clutch; and one-wayconnections between the manually-operable lever and the supplementallever to enable the manually-operable 'mission or power from the motorto the machine; of a pair of clutch-disabling members adapted foralternate operation, one of which members normally locks the otheragainst operation, and disables the clutch; and manuallyoperable meansto shift the normally eflective clutch-disabling member to release itslocking action on the remaining" clutch-disabling member, and to freethe clutch for operation.

30. In a motor driven calculating machine, the combination with a clutchto control the transmission of power from the motor to the machine; of apair of clutch-disabling members, interconnected to adapt them foralternate operation; one of which members normally locks the otheragainst operation, and disables the clutch; manually-operable means toshift the normally effective clutch-disabling member to release itslocking action on the remaining clutch-disabling 8 member, and to freethe clutch for operation; and means operable to return the normallyeffective member to its clutch-disabling position, and to re-establishits locking action upon the remaining clutch-disabling member upon therelease go of the manually-operable means.

31. In a calculating machine, including selector mechanism, thecombination with a register;

a power drive to operate the machine, including a clutch and amanually-operable clutch-control 5 member shiftable between its limitsof travel to render the clutch ineffective or to free it for operation;of an automatically operable clutch control member, likewise shiftablebetween its limits of travel and relatively to the manually-operable 13clutch-control member, 'to render the clutch ineflfective or to free itfor operation; and registercontrolled means to lock theautomatically-operable clutch control member in idle position relativelyto the clutch.

32. In a calculating machine, including selector mechanism, thecombination with a register; a power drive to operate the machine,including a clutch and a manually-operable clutchcontrol membershiftable between itslimits o! travel to render the clutch ineffectiveor to free it for operation; 01' an automatically operable clutchcontrol member; likewise shiftable between its limits of travel andrelatively to the manuallyoperable clutch-control member, 'to render theclutch ineffective or to free it for operation; and register-controlledmeans to lock the automatically-operable clutch control member in idleposition relatively to the clutch; and means actuated by themanually-operable clutch control member and operable upon theautomaticallyoperated clutch control member when the latter is unlocked,to restore it to idle position.

33. In a calculating machine, including selector mechanism, thecombination with a reg-= ister; a power drive to operate the machine,including a clutch and a manually-operable clutchcontrol membershiftable between its limits of travel to render the clutch inefiectiveor to free it for operation; of an automatically operable clutch controlmember; likewise shiftable between its limits of travel and relativelyto the manual ly-operable clutch-=control member, to render the clutchinefiective or to free it for operation; and means actuated by themanually-operable clutch control member and operable upon theautomatically=-operated clutch control member to shift the latter.

.means released for operation as an incident to the release of the lock.for the automatically= operable clutch-disabling means, to renderefifective the locking means for the manuallyoperable clutch controlmember.

35. In a motor-driven calculating machine, the combtion, with a clutchto control the transion of power from the motor to the machine; of apair of clutch-disabling members, either of which alone may becomeeiiective to disable the clutch; means to enable one of theclutch-disabling members when in efiective position to lock the otherclutch-disabling means out of operation; and manually-operable means toshift the first-named clutch disabling member to release its control ofthe other clutch disabling mem= her and to free the clutch foroperation; and means to return said manually-operable clutch disablingmember to clutch-disabling position and thereby restore the second-namedclutch dis abling member to, and lock it in idle position.

36. In a motor-driven calculating machine, the

to difierentialh control the register-actuating a state-deteingmechanism to control the register-actuating mechanism for addition andsubtraction; a drive means for the register=actuating mechanism,including a clutch; and a noally efiective, manually-operableclutch-control member; of normally idle registercontrolled means torender the clutch inefiective when the register attains a predeterminedcondition at a time when the ually operable clutch control member is inits ineflective poshtion; and cable by the state-deterq '1 :u to lockthe manually operable clutch control member in its efiective positionupon its return thereto after the clutch has been rendered ineflectiveunder control of the register.

37. In a motor-driven calculating machine, the

combination with a register on which values may meagre means;manipulative indexing means to differentially control theregister-actuating means; a state-determining means to control theregisteractuating means for addition and subtraction; drive means forthe register-actuating means, including a clutch; and a manuallyoperable clutch control member shiftable into and out of effectiveposition relatively to the clutch; of automatically operable,register-controlled means to disable the clutch when the registerattains a predetermined condition; and means also con trolled by theregister, to lock the manually operable, clutch-control member in itsefiective position.

38. In a calculating machine, the combination with a register;register-actuating mechanism; manipulative indexing mechanism todifierentially control the register=actuating mechanism;

drive means for the register-actuating means, including a clutch; and astate-determining means to control the register-actuating means foraddition and subtraction; of a normally ef= fective, manually operableclutch control member shiitable into and out of efiective positionrelatively to the clutch; a noy idle, supp1e= mental clutch controlmember tripped for operation by the. register; and means to enable oneof the clutch control members to control the other of said clutchcontrol members.

39. In a calculating machine, the combination with a register;register-actuating mechanism; manipulative indexing mechanism todifierentiallycontrol the register-actuating mechanism; and drive meansfor the register-actuating means, including a clutch; of a pair ofclutch control members shiftable into and out of effective positionrelatively to the clutch; and register controlled means to enforcealternate operation of the clutch control members in operations whereinthe capacity of the register is exceeded.

so. In a calculating machine, the combination with a register;register-actuating mechanism; manipulative indexing means todifierentially control the register-actuating mechanism; drive means forthe register-actuating means, including a clutch; and a state controlmechanism to determine when an amount shall be added and subtracted onthe register; of a plurality of clutch-control members shiitable intoand out of efiective position relatively to the clutch; and meanscontrolled by the register and by the state determining mechanism toenforce alternate op eration of the clutch control members in operationswherein the capacity of the register is over= run.

41. In a calculating machine, the combination with a register;register=actuating means; manipulative indexing means to differentiallycontrol the register-actuating means; and drive means for the registeractuating means, including a clutch; of a plurality of clutch controlmembers shiftable into and out of eficctive position relatively to theclutch, one of the clutch control 42. In a calculating machine, thecombination with a register; register-actuating means; manipulative indemeans to difierentially con= trol the register=actuating means; anddrive means for the register-actuating means, includ ing a clutch; of aplurality of clutch control mem= bers shiitable into and out oreficctive position relatively to the clutch, one of the clutch controlmeers being table to its inefiective posi= tion by another of the clutchcontrol a tive position relatively to the clutch; and registercontrolledlocking means to normally look the supplemental clutch control member inits inefiective position, and to lock the main clutch control member inits effective position subsequently to the release of the supplementalclutch control member for operation and its return to.

idle position.

44. In a motor-driven calculating machine, the combination with aregister; register-actuating mechanism; manipulative indexing mechanismto differentially control the register-actuating mechanism; and drivemeans for the registeractuating mechanism, including a clutch; of amanually operable, normally effective clutch control member to interruptthe transmission of power to the register-actuating means; and anormally idle supplemental clutch control member automaticallycontrolled by the register upon the occurrence of a predeterminedcondition therein, and by the manually operable clutch control member,to shift into effective position relatively to the clutch when themanually operable clutch control member is in idle position.

45. In a motor-driven calculating machine, the combination with aregister; register-actuating mechanism; manipulative indexing mechanismto differentially control the register-actuating mechanism; and drivemeans for the registeractuating mechanism, including a clutch; of amanually operable, normally effective clutch control member to interruptthe transmission of power to the register-actuating means; and anormally idle supplemental clutch control member automaticallycontrolled by the register upon the occurrence of a predeterminedcondition therein, and by the manually operable clutch control member,to shift into eflective position relatively to the clutch when themanually operable clutch control member is in idle position; and meansactuated by the manually operable clutch control member incident to itsreturn to effective position, to shift the supplemental clutch controlmember to its idle position preparatory to being again locked in suchidle position.

46. In a motor-driven calculating machine, the combination with aregister; a clutch to control the transmission of power from the motorto the register; a lever normally adapted to hold the clutch disengaged;and manually operable means to shift the lever to enable the clutch tofunction; of a supplemental lever shiftable into the path of the clutchto disengage the clutch; and a locking pin to normally hold thesupplemental lever inactive, and, automatically releasable upon theoccurrence of a predetermined condition in the register.

47. In a calculating machine, the combination with a register on whichnumbers may be added and subtracted; a drive shaft to actuate theregister; a clutch to render the shaft eflective or ineffective; and astate-control mechanism to de- 106 termine whether a number shall beadded or subtracted on the register; of a manually operableclutch-release member adaptedto normally hold the clutch disengaged; asecond. normally idle, clutch release member automatically operable to110 eflect disengagement of the clutch; and means to restore theautomatic clutch-release member to its normal position, and operableincident to the return of the manually operable clutch-release member toits normal position.

RALPH C. COXHEAD.

